this is a new one for me...but then a lot of them are. I would first suggest you check resistances cold and compare between the two. I would suggest there is trouble with the side that has variable LED brightness. The volume know thing is quite weird IMO. Confirm your pin connections, sometimes mirror image/dyslexia-like symptoms have bitten me on the back side.Check ground to grid, ground to cathode, check that grid-ground resistance is dependant on volume position, and check input jack-ground DCR. If you get somethig unexpected, post your findings.
Some ballparks, input jack-ground ~100kOhm
grid-ground 0 at minimum vulume, 100k at max.
regards,
Douglas